How many solar panels would it take to equal a nuclear reactor?




The world is becoming more and more energy hungry, with more and more devices, appliances and vehicles connected to the grid. This is largely what makes widespread adoption of renewable energy sources like solar panels difficult, especially compared to the monumental power of a single next-generation nuclear reactor. Solar panels and nuclear reactors can produce electricity, but it would take more than 8.5 million solar panels receiving light 24 hours a day to generate the same type of output that a nuclear reactor is capable of producing.

While a nuclear power plant requires a significant investment in infrastructure to be operational, a solar panel plant, although a renewable energy source, is not exactly free to build. Building the enormous number of panels needed to match a reactor’s output, not to mention developing safe ways to store excess energy and connect it to local power grids, unfortunately means that all-solar use is simply not yet feasible, at least in the same way as passive nuclear power. That said, countries and governments have been experimenting with ways to compartmentalize and encourage the installation of solar panels, such as placing them on top of parking lots, which could eventually help make up the difference.

It would take 8.5 million solar panels to equal one reactor

Any type of large-scale energy source is measured by the capacity of the energy it can generate. This capacity is not just a raw reading of energy coming in and going out, it is what determines the level of electrical stress that individuals connected to the grid could place on it before it becomes overloaded. Part of what makes nuclear reactors so attractive is that, of all types of energy sources, they have one of the highest rated capacities. An average nuclear reactor has an output of around 900 megawatts, although larger nuclear power plants can produce up to 1,600 megawatts.

In contrast, a single solar panel typically generates between 400 and 460 watts of power, under optimal sunlight conditions. For reference, it takes 1 million watts to produce a single megawatt, which means that 400 watts is approximately 0.0004 megawatts. Assuming constant energy production, for solar panels to generate a degree of energy comparable to that of a single nuclear reactor, approximately 4 million would be needed. However, there is an additional factor here: operational efficiency. Nuclear energy has an efficiency of 93% and its production remains generally stable. Solar panels, on the other hand, are only 24% efficient, dropping their overall output from 400 watts to 96 watts. In other words, it would take about 8.7 million solar panels to match the 837 megawatts (93% of 900) of a nuclear reactor.

Again, this assumes optimal sunlight conditions, and considering how far 8.7 million solar panels would extend, assuming you’d get that much sunlight consistently seems a bit unlikely. This is also why it takes so long for solar panels purchased by individuals to cover their own costs.

The hardest part is finding space for the panels

The obvious problem with adopting large-scale solar panels is space. Nuclear power plants aren’t exactly small, but even the largest nuclear power plant in the United States can be contained in a facility measuring about a square mile. In contrast, a dedicated solar power plant would need more than 14 square miles to achieve this power. Only certain parts of the world have the kind of flat, sunny terrain needed to make this work in the first place, and whether or not it’s available in bulk is another matter entirely.

That said, some countries have found clever ways to increase the presence of solar panels, or even bring them to a level comparable to nuclear power. France, for example, passed a law in 2023 requiring parking lots larger than 1,500 square meters (~16,145 square feet) to be at least 50% covered in solar panels. It’s a clever way to exploit the heat island effect that often affects parking lots, and while it would take a lot of parking lots to rival a nuclear reactor, it’s a good start that most developed countries could also benefit from.